Phase II study of monthly pasireotide LAR (SOM230C) for recurrent or progressive meningioma.

2040 Background: Patients with recurrent or progressive meningiomas who have exhausted surgical and radiation options have limited remaining treatment choices. Somatostatin receptors are expressed in nearly 90% of meningiomas, and somatostatin inhibits meningioma growth in vitro. The somatostatin analog octreotide had promising results in a pilot clinical study. Pasireotide LAR is a long-acting somatostatin analog that has higher binding affinity for most somatostatin receptor subtypes than octreotide. METHODS This is an open label, single arm phase II trial of monthly pasireotide LAR 60 mg intramuscularly in patients with recurrent or progressive intracranial meningioma. Treatment cycles are 28 days. Treatment continues until progressive disease or unacceptable toxicity. Restaging MRIs are performed every 3 cycles and response is assessed using Macdonald criteria. Octreotide scans are performed in all patients at baseline. RESULTS Twenty-six participants have been accrued, 17 (65%) of whom have atypical/malignant meningiomas, median age 56 (range 36-74), 11 men (42%), median KPS 85 (range 60-100), and 22 (85%) with previous radiation therapy. Twenty-two tumors (85%) show at least intermediate octreotide uptake. There are no radiographic responses. Of 22 evaluable patients, 16 (73%) achieved stable disease. Median PFS overall is 20 weeks (95% CI: 9-21) and PFS6 29% (benign meningiomas - median PFS 27 weeks [95% CI: 8-not yet reached], PFS6 50%; atypical/malignant meningiomas - median PFS 16 weeks [95% CI: 8-20], PFS6 20%). Toxicity has been mild except for grade 3 hyperglycemia in 5 (19%) patients, grade 4 hyperglycemia in 1 (4%) patient, and grade 3 lipase in 2 (8%) patients. CONCLUSIONS Pasireotide LAR is a well-tolerated somatostatin analog that is under investigation for heavily pre-treated, recurrent meningiomas. Updated results will be presented at the meeting.